Sawmill.



No. 872,038. PATENTED NOV. 26, 1907. T. S. WILKIN.

SAWMILL.

APPLICATION FILED MAR. 7. 1904.

2 SHEETS-SHEET 1.

PATENTED NOV. 26, 1907.

T. S. WILKIN.

SAWMILL.

APPLICATION FILED MAR. 7. 1904.

2 SHEETS-SHEET 2.

. l g g WWMC THEODORE S. WILKIN, OF MILWAUKEE, WISCONSIN.

SAWMILL.

Specification of Letters Patent.

Patented Nov..2 6, 1907.

Application filed March 7. 1904:- Serial No. 196,875.

To all whom it may concem:

Be it known that I, THEODORE S. WILKIN, a citizen of the United States, and resident of Milwaukee, in the county otMilwaukee and State of Wisconsin, have invented certain new and useful Improvements in Sawmills; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention has relation to improvements in power feed cylinders, more especially intended, although not necessarily, for use in connection with saw mill machinery for operating and controlling the saw mill carriage, the set works, and the knees and dogs thereon. The invention, however, is equally applicable as a power feed for supplying fluid under pressure to any mechanism to be operated. A

One of the objects of the invention, broadly considered, is to provide a construction whereby a continuous and practically uniform pressure is maintained inside a cylinder from which the steam, or other fluid pressure, is conveyed to the mechanismto be operated, the said continuous and uniform pressure being maintained at all times, either when the piston is moving or at rest.

A further object of the invention, broadly considered, is the provision of a construc: tion a hereby a feed is provided which is economical in the use of steam, inasmuch as the steam is exhausted from the front of the piston only to the amount required to move the piston a desired distance.

A further object contemplated, particularly when the mechanism is employed in connection withsaw mill machinery, is to obviate the use of a telescopic pipe, such as shown in Patent No. 317,256, issued to me on May 5, 1885, and'at the same time preserving all the advantages possessed by the construction covered in said Letters Patent, while eliminating the disadvantages of a leaky packing gland caused by the telesco ic pipe wearing flat on the bottom, and also y the weight and drag of said pipe on the carriage and feed.

K still further object contemplated is the provision of a safety stop for the piston.

and carriage, whereby the possibility of the carria e' and piston getting beyondthe control oi the sawyer, and running away, with resulting damage to the cylinder, or the knocking out of the head of the same, or the breaking of the carriage, or of the piston rod, or of allthese contingencies, is avoided.

The mechanism which cil'ects the above pointed out objects is embodied in a simple, easily operated, strong and reliable construction, capable of being constructed at a minimum expense, and with a saving in weight, wear, together with the least loss of steamand complication of parts.

The inventionconsists of the mechanism its parts, and combinations of parts, as herein described and claimed, or the equivalents thereof.

In the drawings, Figure 1 is a side elevation of a saw mill carriage, with its head blocks, knees and motor mounted thereon, and with my improved feed in proper relation thereto, certain parts being in section. Fig. 2 is a similar view, on an enlarged scale, parts being broken away, and the saw mill carriage and related parts omitted; Fi 3 is a section on the line 3-3 of Fi 2; and Fig. 4 illustrates a modification in the connection for the sawyers lever.

The construction of the carriage, blocks, knees and motor is shown in the drawings only in outline, as such mechanism is common in saw mills and forms no part of my invention, except only as the same are related to my invention in showing its combination with a traveling carriage such, for instance, as a saw mill carria e, for supply ing the actuating medium to sai carriage.

Referring to'the drawings, a designates a valve casing. The main or valve chamber of this casin is in communication with two steam ports Q, and with an alined inter mediate steam port S. Movably fitted in'the main valve chamber of the casing is a valvestem which is formed or provided with two valves, one of said valves occupyin an intermediate position on the stem, and designated by the letter T, and the other being at the lower end of said stem, and designated by the letter t.

Extending from the valve casing, and communicat1ng with o osite ends of a cyllnder m are steam pipes -K. A T-crank L is connected to t e upper end lengths of the pipes K-K, intermediate of the ends of said pipes, are valve casings. In the valve casing of the pipe K is s'wingingly mounted a butterfly valve 9, and in the valve casing of the pipe K, is fitted a similar but- The central stems of these valves are extended to the outside of the casin s, and have mounted on their outer ends ell crank levers Spanning the valvecasings in which the valves 9-9 are located are y-pass pipes h-h in which are located byass check'valves.

Attached to the cylinder, m and the mill floor at J -J are levers J J which are substantially in the form of hell crank levers, their upper arms or members being normally at an incline or obliquity from their pivots, and their lower arms depending from said pivots at substantially right angles to the upper arms. These lowere arms of the levers are connectedto the bell crank levers jj by means of rods 2-2.

' The letter M designates a sawyers lever for controlling the valve T aud t. The lever is pivoted at the oint O and is connected to the T-crank L y means of rods which are pivoted to the lever M at the points St and to the T-crank at the points pp.

Within the feed cylinder m is the iston red 0 provided at its outer end with a ead :c

which is pivoted to abracket y. The bracket 'y swings on a rod 3]. A pipe F is connected to the piston rod by means of a universal joint E, and pipe leadsto the motor, or other mechanism mounted on the carriage B,

and which-motor or mechanism is to be supplied with-the fluid medium under pressure.

A piston c is adapted to reciprocate in the cylinder m (seeFig. 2). This piston is preferably in the form of a hollow body, and at opposite ends thereof is rovided with openin s which are controllei by means of checkva ves A. and H. The pi ton rod C is tubular, forming a passage w longitudinally thereof, and which passage extends through said piston rod, or to a point where the piston rod' intersects with thepipe F. The portion of the piston rod within the hollow chamber of tlip piston is provided with an inlet openmg An inlet pipe t leads to the valve casing a, and is'adapted for conveying steam, or fluid under pressure, into said casing, and an exhaust pipes leads from said casm When my invention is employed in connection with saw mill machinery, the carriage B may be of any length, proportion, or material, or, in other words,- may be of ordinaryconstruction, provided with wheels or slideways, and made to travel in a straight line by the saw, and can be made to set off from v the saw line when gi ging, and set u to the saw line when fee mg, as is usua. The length of 'the cylinder B is determined by the longest log to be sawed, and the amount I of cushion in the cylinder desiredr The distance between the levers JJ should be the distance required for sawing the longest lo lvly invention-contemplates the omission altogether of the levers J J and the valves gg and h-h, and in that case the length of the cylinder is to be determined by the travel of the carriage to saw the longest log.

In Fig. l the carriage is shown at the extreme end of the stroke of the piston toward the right, the piston having been stopped by the carriage coming into contact with and running on to the lever J at the right. The

contact of the carriage with the said lever J has the effect of depressing the upper arm of said lever and turning the lower arm thereof toward the left, whereby a push'is exerted on the right hand rod '2, and consequently the right hand butterfly valve g is turned to a closed position. When this occurs the opportunity of the steam in advance of the right hand of. the piston c to escape is cut off (the by-pass valve h of course seating itself by the action of the gravity and the steam pressure thereon). The piston is, therefore, brought to a stand still.

To move the carriage from the position shown in Fig. '1 (toward the left or to feed it up) the lever M is thrown to the position illustrated in Fig. 1, that is, toward the left. This through the rods ff, Tv -crank 'L, and link 1, will cause a down movement of the valve stem in casing a, andbring the valves T and t to the position illustrated in the drawings. Steam is now free to flow from the boilers or generators through the pipe t, thence into the upright passage t in the valve casing a, the said passage communicating at opposite ends with the steam ports RIt In the adjustment of the two valves referred-to, however, the lower valve t pretering the passage 25 is free to flow into port R, thence into port Q, and from said latter port into pipe K by way-of a communicating passage-between said port and pipe. When the carriage is in the position shown in Fig. 1 the butterfly valve g is in its closed positlon. The steam entering pipe K, therefore, at the start will pass by way of the byipe, raising valve h, and thence entering t e cylinder, where it acts on the piston c, and causes'said piston to move toward the left, and of course carries the piston rod and the carriage in the same direction. When the carriage has moved in this direction a sufficient dlstance to allow the lever J to raise and open the valve g by means of the weight shown, or equivalent means, then the steam will pass directly through the pipe K. During this period of feeding the carriage, (or moving it to the left) boiler pressure is maintained on the right hand side of the piston, and on check valve A. The check valve A is there by opened, and the steam admitted to the interior of the piston, effecting the closing of valve H, and passing from the interior of said piston through the inlet port V, thence along passage to of the piston rod, and by way 0 the pipe F to t e motor, or other mechanism to be supplied with the fluid under pressure. Boiler pressure is therefore maintained not only on the right hand side of the piston, but also on check valve A and in hollow piston C. At the same time only enough steam is exhausted from the left hand side of the piston to move the carriage the desired speed and distance, the left hand butterfly'valve 9 being open and the check valve it closed, the period of exhaust being regulated by the sawyers lever M, and the desired speed of the carriage is obtained by exhausting the fluid under pressure, through the medium of the lever M, only to the extent of the speed desired. The steam which is exhausted from the left hand side of the piston asses down the pipe K, thence enters the va ve casing and thence flows along a passage therein which communicates with the steam port Q, thence into the port S, and out through the exhaust pipe 8.

When the carriage is at rest, the valves T and t are in the position shown by dotted lines in Fig. 2, and in such position steam is admitted intothe cylinderm against both sides of the piston, and consequently the pressure is equal on both sides of said piston, and on valves. H and A, and in hollow piston rod C and pipe F.

To move the carriage to the right, or to gig it, the lever M is thrown in a reverse position to that shown in Fig. 1. This will have the effect of raising the stem of valves T and 23" so as to bring valve T in position to close off communication between steam ports R and Q, and raise valve t so as to openu communication between steam ports R and The result is that the steam which enters passage t from the inlet pipe t will flow into ort R, thence into 1port Q, thence by way 0 a passage to pipe and by way of said ipe to the space of the cylinder on the-left lland side of the piston c. The said piston and its rod, as we 1 as the carriage B, will'now be moved toward the right, and in this movement of the parts the steam will open valve H and close valve A. The opening of valve H admits steam to the mterior of the hollow piston. The steam so admitted thence flows through the port V to the passage w of the piston rod, and thence by way 0 said passage to the pipe F. The steam on the right hand side of the piston will be forced through pipe K (butterfly valve 9 being opened, and by pass valve-h being closed), thence by way of said pipe to the passage in the valve casing with which said pipe communicates, thence by way of said passage to the port Q, thence to port S, and finally out through exhaust pipe 8.

No matter in what direction the carriage is running, it the sawyer for some unforeseen cause or neglect fails to reverse the lever M and valve T in time, the carriage will continue to run until it strikes either of the levers J, when of course one or the other of the valves g or g will be closed (check valves It or k closing by gravity and the steam pressure) and a cushion thereby formed which will effect the stopping of the piston and carriage. The length of the cushion at either end of the cylinder is determined by the relative position of the levers J-J and the ends of'the cylinder.

The operating lever M is connected with 'the valve stem of the-valves T and t in the manner shown in order to prevent the expansion and contraction of the pipes K-K changingperceptibly the position of said valves T and t. vertically, the links L and Z being allowed to swing as the T-crank is held in position by the lever M and the connecting rods In the modlfication illustrated in Fig. 4, the depending arm of the bell crank lever L is omitted, and the lower rod f extends from the pivot of the lever M to the pivot of the lever L,- while the upper rod f extends from the lever M at a point above the pivot of said lever to the extremity of the upper arm of the bell crank lever L.

ton-rod C- is provided at its outer end with a head x which is pivoted to a bracket y, and that the bracket 'y swings on a rod 1 disposed at right angles to said pivot which connects the head m of the piston rod to the bracket It will be understood that the carriage swings over the iston rod when an offset is being used on a and mill carriage, and that the carriage is offset g inch in gigging the log for another cut, but the piston rod is supposed to remain on a line with the cylinder. It will be further understood that piston-rods in some saw mill constructions are 50 feet long, and when they are run.clear out of the cylinder, as one end is fastened to the bracket on the carriage, and the other end is fastened to the piston, the piston-rod will sag or bend down in the middle, and will break off at the joint where it is attached to the bracket on the carriage, unless this joint is made flexible. By my construction, wherein the pivotal connection is formed at the end of the piston-rod, the above pointed out difficulties are overcome, inasmuch as the pivot formed by the rod y will permit of the carriage swingin over the piston-rod, and will also permit 0 flexibility at the end of the piston-rod, which is It has heretofore been stated that the pisso essentialwhere long piston-rods are used, as previously explained. As the pipe F extends from the hollow piston-rod and leads to the motor, it is of course, under my and adapted. for controlling the admission and exhaust of the fluid under pressure to and-:from the cylinder, means for operating the valve mechanism whereby thesfluid under pressure is admitted to one or both sides of the piston in the cylinder at all times either when the piston is moving or at rest, and when admitted to both sides thereof an equal pressure is maintained on said sides, and means for conveying the fluid pressure so admitted to the cylinder to a mechanism to be operated thereby.

2. In a power teed cylinder, the combination of a cylinder, a piston therein, a hollow piston rod extending from the piston and constructed to receive the fluid under pressure which enters the cylinder from either end thereof and convey said fluid to a mechanism to be operated, valve mechanism inconnection with the cylinder and adapted for controlling the admission and exhaust of the fluid under pressure to and from the cylinder, and means for operating the valve mechanism, whereby the fluid under pressure is admitted to one or both sides of the piston. in the cylinder at all times either when the piston is moving .or at rest, and when admitted to both sidesthereofan equal pressure is maintained'on said sides, the fluid pressure so admitted to the cylinder passing into the hollow piston rod to the said mechanism to be operated.

3. In a power feed cylinder, the combination of a cylinder, a piston therein, check valves on both sides of the ,piston, one adapted to open and the other adapted to close when pressure is exerted against the piston in'one direction, and vice versa when pressure is exerted a ainst the piston in the opposite direction,va lve mechanism in connection 'with the cylinder and adapted for controlling the admission and exhaust of the fluid under' pressure to and from the cylinder, means for operating the valve mechanism, whereby the fluid under pressure is admitted to one or both sides of the piston in the cylinder at all times either when the piston is moving or at rest, and when admitted to both sides thereof an equal pressure is maintained on said sides, and means for conveying the fluid pressure so admitted to the cylinder to a mechanism to be operated.

valves at opposite ends of the hollow piston,

one adapted to open and the other to close when pressure is exerted against the piston in one direction, and vice versa when pressure is exerted thereagainst in the opposite direction, valve mechanism in connection with the cylinder and adapted for controlling the admission and exhaust of the fluid under pressure to and from the cylinder, means for operating the valve mechanism, whereby the fluid under pressure is admitted to one or both sides of the piston in the cylinder and into the interior of said piston at all times either when the piston is movingor atrest, and when admitted to both sides thereof an and within said piston, and means for conveying the fluid under pressure from the interior of the hollow piston to a mechanism to be operated.

5. In a power feed cylinder, the cor'nb'ina tion witha cylinder, a hollow piston therein, check valves at opposite ends of the hollow piston, one adapted to open and the other to close when pressure is exerted against the pis ton in one direction, and vice versa when pressure is exerted thereagainst in the opposite direction, a hollow piston rod in commu nication with the interior of the hollow piston, and extending from said piston and ad apted to convey the fluid under pressure'irom the interior of the piston to amechanism to be operated, valve mechanism in connection with the cylinder and adapted for controlling the admission and exhaust of the fluid under pressure to and from the cylinder, means for operating the valve mechanism, whereby the fluid under pressure is admitted to one or both sides of the piston'in the cylinder and into the interior of said piston at all times either when the piston is moving or at rest, and when admitted to both sides an equal pressure is maintained on said sides and within said piston, and means for conveying the fluid under pressure from the interior of the hollow piston through the hollow piston rod, to the said mechanism to be operated.

' 6. In a power feed cylinder, the combination with a cylinder, a piston therein, a valve casing having an inlet pipe leading thereto from a source of supply of fluid under pressure, and an exhaust pipe leading therefrom, and also having two. pipes extending therefrom, and leading to opposite ends of the cylinder, valve mechanism in the casing, means for operating said valve mechanism, whereby the steam admitted into said casing through the inlet pipe is per} mitted to pass through one or the other of the pipes leading to the cylinder at all times either when the piston is moving or at rest,

equal pressure is maintained on said sides and when admitted at both ends of the cyl opposite sides of the piston, and when permittedto passthrough only one of said ipes is exhausted through the other pipe and ack to the valve casing and out of the exhaust pipe thereof, and means for conveying the lluid under pressure admitted to the cylinder to a mechanism to be operated.

7. In a power l'eed cylinder, the combination of a cylinder, a piston therein, valve mechanism in connection with the cylinder, adapted for controlling the admission and exhaust ot the lluid under pressure to and from the cylinder, a valve controlled conduit leading from the valve mechanism to the cylinder, a movable part carrying a mechanism to be operated by the iluid under pressure, means for conveying the fluid under pressure l'rom the cylinder to said mechanism to be operated, a lever adapted to be operated by the movable part after said movable part. has moved a certain distance. a connection between said lever and the valve of the conduit, and adapted, when the lever is operated, to automatically shut off the supply of the lluid under pressure to the cylinder, means, when the movable part leaves the lever, lor automatically opening the valve of the conduit, and a by-pass pipe bridging the valved portion of the conduit, said by-pass pipe having therein an upwardly opening valve.

8. 111 a power l'eed cylinder for saw mill carriages, the combination of a cylinder, a piston therein, a saw mill carriage, a motor carried on said carriage, a hollow piston rod extending from the piston and pivotally connected to the saw-mill carriage, a pipe connected to said motor and said hollow piston rod and provided with means for allowing the carriage to be oll'set, and means whereby lluid under pressure is supplied through the hollow piston rod and the pipe to said motor.

0. In a power teed cylinder, the. combination ol a cylinder, a piston therem, a valve casing, pipes leading from the valve casing to the cylinder valve mechanism within the casing and adapted for controlling the admission and exhaust oi the fluid under pressure to and from the cylinder, said valve mechanism provided with a projecting valve stem, at pivoted operating lever, and a yielding connection between said lever and the valve, whereby any variations in the valve. laterally caused by expansion and contraction of the pipes leading from the valve casing, will not ell'ect the valve mechanism vertically, the said operating lever when actuated operating the valve mechanism and causing the lluid under pressure to be admitted to and exhausted from the cylinder.

10. In a power feed cylinder, the combination of a cylinder, a piston therein, a valve casing, pipes leading from the valve casing to the cylinder, valve mechanism in the casing adapted for controlling the admission and exhaust of the fluid under pressure to and from the cylinder, said .valve mechanism provided with a projecting valve stem, a bell crank lever having one arm pivotally con- 1 nected to the valve stem, a support pivoted at one end to a fixed part and at its opposite end to the bell crank lever, a pivoted operating lever, and rods pivoted to said lever, and extending and pivoted to the bell crank lever, the said operating lever when actuated operating the valve mechanism and causing the lluid under pressure to be admitted to and exhausted from the cylinder.

11. In a power l'eed cylinder, the combination of a cylinder, a piston therein, means for feeding fluid under pressure to the cylinder, a movable. part carrying a mechanism to be operated by the lluid under pressure, means for conveying the lluid under pressure from the cylinder to the said mechanism to be operated, and means alter the movable part has moved a certain distance for automatically shutting oil the supply of the lluid under pressure to the cylinder.

12. In a power l'eed cylinder, the combina-- tion of a cylinder, a piston therein, means for feeding lluid under pressure to the cylinder, a movable part carrying a mechanism to be operated by the lluid under pressure. means for conveying the lluid under pressure l'rom the cylinder to said mechanism to be operated, and means alter the movable part has moved a certain distance in either direction for automatitailly shutting oll the sup- I ply ol' the lluid under pressure to the cylinder.

13. In a power l'eed cylimler, the combination ol a cylinder, at piston-therein, valve mechanism in connection with the cylinder, adapted for controlling the admission and exhaust ol' the lluid under pressure to and from the cylinder, a valve controlled conduit leading from the valve mechanism to the cylinder, a movable part carrying a mechanism to be operated by the fluid under pressure, means for conveying the lluid umler pressure from the cylinder to said mechanism to be operated, a lever adapted to be operated by the movable part after said movable part has moved a certain distance, a connection between said lever and the valve of the conduit, and adapted, when the lever is operated, to automatically shut oil the supply of the lluid under pressure to the cylinder, and means, when the movable part leaves the lever, for automatically opening the valve ol the conduit.

14. In a power feed cylinder, the combination of a cylinder, a piston therein, valve mechanism in connection with the cylinder, and adapted for controlling the admission and exhaust of the lluid under pressure to and from the c linder, valve controlled conduits leading lrom the valve mechanism to the cylinder, a movable part carrying a mechanism to be operated by the fluid under pressure, means for conveying the fluid unf der pressure from the cylinder to said mechanism to be operated,,levers adapted to be operated by the mom ble part after said movable part has moved a certain distance in either direction, and connections between said levers and the valves of the conduits, and adapted, when the levers are operated, to automatically shut off the supply of the fluid under pressure to the cylinder, and means, when the movable part leaves either of said levers, for automatically opening the valve of the conduit controlled by the said lever.

15. In a power teed cylinder, the combination of a cylinder, a piston therein, valve mechanism in connection with the cylinder and adapted for controlling the admission and exhaust of fluid under pressure to and 1 from the cylinder, a conduit extending lrom the valve mechanism to the cylinder, a normally open valve in the conduit, a movable 1 part carrying a mechanism to be operated by the fluid under pressure, means for conveying the fluid under pressure from the cylinder to said mechanism to be operated, a lover adapted to be operated by the movable part,

after said movable part hasmoved a certain distance, a rod extending from the lever to the valve stem of the conduit valve, whereby when the lever is operated by the movable part the valve is turned in a direction to shutoff the conduit, and means after the movable part leaves the lever for automatically opening the valve of the conduit.

16. In a power feed cylinder or saw-mill carriages, the combination of a cylinder, a

1 piston therein, a saw-mill carriage, a motor carried on said carriage, a hollow piston rod extending from the piston and pivotally connected to the saw-mill carriage, a pipe con- 3 nected to said motor and having a universal joint connection with the hollow piston rod, and means whereby fluid under pressure is supplied through the hollow piston rod and the pipe to said motor.

In testimony that I claim the foregoing I have hereunto set my hand at, Milwaukee in the county of Milwaukee and State of VVisconsin in the presence of two witnesses.

THEODORE S. VVILKIN.

Witnesses:

J. W. FLYNN, II. C. McDEmwo'nr. 

